Haworthia retusa

Taxonomy
Scientific Name
Haworthia retusa (L.) Duval
Higher Classification
Monocotyledons
Family
ASPHODELACEAE
National Status
Status and Criteria
Data Deficient - Taxonomically Problematic
Assessment Date
2014/03/24
Assessor(s)
L. von Staden, R.R. Klopper & J.C. Manning
Justification
A taxonomically problematic species that is difficult to distinguish from H. mutica, as well as some forms of H. pygmaea. Until taxonomically resolved, its risk of extinction cannot be assessed.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Bredasdorp and Swellendam to Mossel Bay.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Fynbos
Description
Stony, shale soil with very short bushes and a covering of pebbles on the ground.
Threats
Threatened by habitat loss to expanding crop cultivation, urban expansion and overgrazing. Illegal collecting for the specialist succulent horticultural trade is also causing losses to subpopulations that occur in accessible sites.
Population
Population trend
Decreasing
Notes
Haworthia has been plagued with an overprolification of names, recognising variation over similarity, and causing much confusion (Bayer and Manning 2012). The genus needs to be revised using population-level molecular techniques in order for species concepts to be resolved (J.C. Manning pers. comm. 2014).
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Haworthia retusa (L.) DuvalData Deficient (Taxonomically Problematic) 2014.1
Haworthia retusa (L.) DuvalEN A2bc2013.1
Haworthia retusa (L.) DuvalVU A2a2012.1
Haworthia geraldii C.L.ScottThreatened 2012.1
Haworthia turgida Haw. var. suberecta Poelln.Threatened 2012.1
Haworthia mutica Haw. var. nigra M.B.BayerEN B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)Raimondo et al. (2009)
Haworthia turgida Haw. var. longibracteata (G.G.Sm.) M.B.BayerLeast Concern Raimondo et al. (2009)
Haworthia turgida Haw. var. turgida Least Concern Raimondo et al. (2009)
Haworthia geraldii C.L.ScottThreatened Raimondo et al. (2009)
Haworthia turgida Haw. var. suberecta Poelln.Threatened Raimondo et al. (2009)
Haworthia retusa (L.) DuvalVU A2aRaimondo et al. (2009)
Bibliography

Bayer, M.B. 1999. Haworthia Revisited: A revision of the genus. Umdaus Press, Hatfield.


Bayer, M.B. and Manning, J.C. 2012 (Updated online 2013). The Haworthia nomenclator: A list of accepted species with some guidelines for infraspecific names. Haworthia Update 7(4):30-40.


Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.


Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.


Scott, C.L. 1985. The genus Haworthia, a taxonomic revision. Aloe Books, Johannesburg.


Citation
von Staden, L., Klopper, R.R. & Manning, J.C. 2014. Haworthia retusa (L.) Duval. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2018/11/16

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